Toy helicopter



May 27, 1952 R. R. cARRlNGToN TOY HELICOPTER 2 SHEETS-SHEET l Filed Sept. 17, 1946 INVENTOR.

R. R. CARRINGTON May 27, 1952 Filed Sept. 17, 1946 2 Simms- SHEET 2 INVEVTOR, i 2Q Patented May 27, 1952 UNITIDy STATES PATENT yQFF'ICE TOY 'HELICOPTER Roy R. Carrington, Fulton, Mo. Application September 17, 1946, Serial No. 697,491

( Cl. 1G-75 6 Claims.

The 'invention relates generally to iiying toys and more particularly to a toy helicopter.

The general object of the invention is to provide a novel toy helicopter in a form which may be inexpensively constructed and which is capable of effecting night for a sustained period of time.

' Another object is to provide a toy helicopter having a bladed rotor adapted to assume automatically a pitch suitable for ascent when the rotor is driven, and a different pitch for descent.

A further object is to provide a toy helicopter having a bladed rotor adapted to assume a pitch suitable for ascent when the rotor is driven, and another pitch suitable to effect autorotation when the device is descending.

Still another object is to provide a toy helicopter having a pair of bladed rotors driven in opposite directions to nullify the torque effect of a single rotor and with the blades of the upper rotor so supported as to provide for automatic adjustment thereof to provide pitches suitable both forascent and descent.

Other objects and advantages will become apparent from the following connection with the accompanying drawings, in which:

Figure l is a sidel elevational view on a reduced scaleof a toy helicopter embodying the features of the invention.

Fig. 2 is a view similar to Fig. 1 but taken in a plane at rightangles to that ofFig. 1.

Fig; t?.` is a plan view of the toy shown in Fig. 1.

Fig. 4 is aV vertical sectionalv View taken on they line 41.-4 offFig. 1.

Fig. 5- is a fragmentaryv sectional view taken on the line 5 5 of Fig. 1.

Eig. 6 is a sideelevational view similar to Fig. 1i showinga modified form of construction.

Fig; 'if is a plan view of the device shown in Fig'. 6.

Eig. 8. is: a fragmentary sectional view taken on theline 8.8.of'Fig. 6.

Fig. 9y isa plan View of of'helicopter.`

Fig. 1.0 isa side elevational view similar to Fig: l; butyshowing the modified' form of Fig. 9'. Figiglil isaside elevational' view in aplane at rightanglesfto the plane of Fig. 1'0 and? showing thef device', when the. power of the drive motor haabeQneXpended.

Fig; 12de a view similar to Fig. 1v1 but showing the; position; of the parts thereof when the drive motor-isreadyfonoperation.

another modied formv helicopters have. heretofore been condescription taken in n structed in a manner to provide oppositely ro-l tating rotors driven by a motor such a rubber band motor, but very little if any attention has been given to the question o'fvoper'ation of 'the device after the drive motor has expended its power. In many prior structures. the device merely plunged to earth Without any attempt being made to control the descent. In other prior structures, a parachute has been attached to the device to control the descent, butin hone of them has an attempt been made to utilize lthe rotors to control the descent. I

With the present invention, the helicopter is so constructed that one of the rotors controls the descent in such a manner as to cause the de'- vice to descend in an upright position at a relatively slow rate so thatthe descent is just as much a feature of the device as isu the ascent. To this end, one of the rotors of the device is provided with a pitch suitable to cause aiitorotai tion thereof which results in a smooth, relatively slow downward movement of the device. Such pitch of the rotor, however, is usited to effect a rapid climb of the device Whe being drive by the drive motor. 'I-he device,- therefore', provides means for automatically increasing the pitch of the" rotor as an'- incident to its being driven by the' drive motor'. When -the drive motor has eik# pended its power' and ascent isompleted, the rotor returns to its normal position with a pitch suitable for the above mentionedautorotatio'n. Such relatively slow descent not only increases the time andi manner' of flight vbut also'- avoids damage tothe device through impact with the earthV when descending at v a faster rate. The structure of the. device;n therefore, need not-be' as rigid asl heretofore necessary and consequently less weight isinvolved and the device can be causedr to ascend to' a reaterheiglit'v for a; givenv motor power.V

In al1-of the embodiments shown herei'rLvI provide. a body structure carryingv a rotor ,at'its lower end' with a second rotor of! much larger diameter locatedl adjacentthe upper end. The lower rotor isrotatablerelative'tothe body while'I the upperv rotor is 'x'ed to the bodyfor rotation` Mounted Within the` b'ddy iS' ai mdtl" preferably ofthe rubber band'typcohnecte'd to' rotateA the lower rotor in one Idirection and the body withthe upper'ro'to'r in the"opposite= direc tion. The principal feature of' the invention lies" in theA manner'in rotor are attached or connected tothev Bodso that when' the' drive" lrilrto'r has" expended? 't'spower, such blades willv maintaina' pitcl-i of api' proximately 2 to the horizontal which is suitable for autorotation. However, when the rubber band motor is wound up and the opposite rotation of the rotors takes place, as in ascent, the blades of the upper rotor automatically assume a position of increased pitch suitable to effectively carry the craft upward.

In the embodiment shown in Figs. 1 to 5 of the drawings, the body structure comprises in this instance an elongated tube 2G. Such tube may be made of any suitable material of light weight such as plastic material, paper, or thin metal. Located at one end of the tube 20, which end constitutes the lower end in ascent, is a lower rotor 2|. The rotor 2| comprises a pair of oppositely extending blades of relatively steep pitch, the blades being integral with each other and provided with a hub or central portion in the form of a metallic clip 22 wrapped about the rotor. To rotatably support the rotor, a shaft in the form of a wire 23 extends through the clip 22 and is hooked over the lower edge thereof, as at 24, so that the shaft 23 is rigid with the rotor. The shaft 23 extends upwardly into the tube and is provided with a thrust bearing in the form of metallic washers 25 interposed between the clip 22 and a cap 26 frictionally retained on the lower end of the tube 2|).

The drive motor in the present instance is a rubber band comprisingaplurality of strands extending upwardly within the tube 20. The lower end of the rubber band 3B is connected to the shaft 23, a hook 3| being provided on the upper end of the shaft to detachably engage the strands of the rubber band. The upper end of the rubber band is adapted to be secured to the tube 23 preferably at the upper end thereof. To this end I provide a plug 32 mounted in the upper end of the tube and frictionally retained therein. The plug 32 is provided with a pair of ears or drive lugs 33 interfltting with notches formed in the upper end edge of the tube. Extending centrally through the plug 32 is a wire 34 having a hook 35 at its lower end over which the upper end of the strands 30 of the rubber band motor are engaged. Should any of the strands of the motor break, the cap 26 at the lower end of the tube and the plug 32 at the upper end thereof may be readily removed and the ends of new strands of rubber engaged over the hooks 3| and 35.

A second rotor is provided, which preferably is of substantially larger diameter than the rotor 2| and is mounted adjacent the upper end of the tube 20. The upper rotor is rigidly secured to the tube 20 so that when the rubber band is wound by turning the lower rotor 2| relative to the body 2i), the upper rotor and body will rotate in one direction while the lower rotor 2| will rotate in the opposite direction. The upper rotor in the present instance comprises a pair of oppositely extending blades 46 connected by an integral intermediate portion 4| centrally apertured to fit over the tube 29. The intermediate portion 4| is rigidly secured to the tube 20 by means of a clip comprising a band 42 wrapped about the tube 2|) and having a pair of ears 43 extending through slots in the intermediate portion 4|V and bent against the upper surface thereof. The upper rotor thus is secured to the tube 2B for rotation therewith.

The principal feature of the invention lies in the fact that the upper rotor is so mounted that the blades 40 thereof will have an increased pitch when being driven so as to produce a rapid ascent. To this end the intermediate portion 4I of the upper rotor is generally U-shaped with the middle portion of the U rigidly secured to the tube 20 by the clip 42. The two arms of the U extend upwardly along side the tube 20 to merge into the blades 40. When the upper rotor is being driven by the rubber band motor 30, there is a centrifugal force resulting from such rotation which tends to move the blades 40 away from the tube 20 and thus spread the arms of the intermediate or U-shaped portion 4|. Likewise the resistance of the air to the rotation of the blades produces a torque which has a similar spreading effect on the arms of the U-shaped portion. Such spreading of the arms of the U-shaped portion, as is obvious from Fig. 5, will cause the blades 40 to tilt at a greater pitch angle than they normally assume when stationary or when rotating at a slow speed. Thus I may provide a pitch angle of approximately 2 for the blades when in their normal or idling position, which angle is suitable for autorotation and when such blades are driven at a speed sufficient to cause ascent, they may assume a position of substantially increased pitch as indicated by the dotted lines in Fig. 5. Thus. while the device is being driven upwardly bythe rubber band motor, the blades of the upper rotor have a pitch suitable for such ascent. When `the rubber band motor has expended its power, the blades reassume their normal pitch which is suitable for autorotation. The descent of the device thus causes the upper blades to rotate, materially slowing the speed of descent and maintaining the device in an upright position during such descent. To increase the flexibility of the arms of the U-shaped portion 4| and thus increase the angle to which such arms are bent by the centrifugal force and torque, the arms may be structurally weakened to a slight extent at their point of connection with the blades 40. In the present instance, I have increased the exibility by providing apertures 44 adjacent the point where the arms of the U-shaped portion 4| merge into the blades 40.

In the modified form shown in Figs. 6, 7 and 8 I show a toy helicopter in which the blades of the upper rotor are similarly supported to alter the pitch thereof. The structure of the device `shown in these figures, however, differs in a number of respects from that shown in Fig. 1. Thus as shown in Fig. 6 the body structure comprises a pair of elongated side bars 50 arranged in laterally spaced relation to each other and integrally connected at their lower ends by a curved portion 5|. The upper ends of the side bars 50 are interconnected by a fiattened portion 52. Intermediate the ends of the body structure or frame is a reenforcing strip 53 extending from one side bar to the other. The lower rotor here indicated at 54 comprises a pair of outwardly eX- tending blades mounted on a hub 55 secured to a shaft in the form of a wire 56 extending through the curved portion 5|. A thrust Washer 51 may be interposed between the hub 55 and the curved portion 5| to eliminate friction. The upper end of the shaft 56 is provided with a hook 58 adapted to receive the strands of a rubber band motor 6|). The rubber band motor SB extends upwardly between the side bars 5i) and at its upper end it engages a hook 5| rigidly secured to the flattened portion 32 at the upper end of the side bars. The rubber band motor Gil when wound thus will cause the lower `rotor 54 to rotate in onedirection feo eed above 'the errer end t2. tllereef- .Goor neo the blades Wirte the trarne YStrutture ie e .-.ll-sha'pvedrnembel et haring e flattened inter.- nie rete portion' rigidly eeeured to the detiene@ end portion .5..2 of .the frame etrueture- The two of the ...U extend opwardlythererrom and .are eeeured et .their upper or free ende to the ner ende, of the blades ,62. U-ehaped member .63 in this instance has e titiller action to the intermediate portion 4l oi-tlle previously .deeorlbed torm- Thus it .has Suitleient flexibility to permit the centrifugal torte and .torque due to air resistance arising trom rotation of. the upper blades when .driven by the rubber band motor .6o. to cause the arms oi the Ll to fiere outwardly. as indicated in Fig. 8, andA thus increase the angle yof pitch of the blades 5g. as in the case of the previously described term. the blades 62 of the present form will assume an angle of pitch suicient to cause rapid attent when beine driven by the rubber band motor 6p but when the latter has expended its power, the blade 62 will assume a lesser angleof pitch suitable for autorotation during descent.

In the modied form 'shown in Figs. 9 to 12, inclusive, I have provided a device having a body or frame structure generally similar to that .SIIQWH in Eig f- Thus I PTQYie ai P ll 0f laetr' ally Vspaced elongated side bars 1 1; having curved interconnecting portions 'H at both ends. At the lower end'of the frame I provide arotor comprising blades 'l2 connected to a shaft 'i3 extending through' the lower curved Vportin 'H Awith a thrust wwasher 'l interposed therebetweenfThe upper end of the shaft 'i3 is formed interaJ hook 'l5 to receive the lower end of a rubber band motor 16. The upper end of the rubber band motor is engaged over a hook 'Vl rigidly secured to the upper curved portion H so that when the rubber band motor is wound up, the frame structure will be rotated in one direction while the lower rotor blades 'I2 will be driven in the opposite direction.

The upper rotor in this instance comprises a pair of oppositely extending blades B0 which are directly connected to the respective side bars 10, andthe side bars are made of flexible material adapted to be bowed by increased tension of the rubber band motor 'I6 when the latter is wound to increase the pitch of the blades 80 when the rubber band motor is driving the device. 'Ihus as illustrated in Fig. l1, the rubber band motor 'I6 when unwound will exert only a slight tension on the two ends of the frame structure causing the side bars 'I0 to assume a predetermined position. With such position of the side bars, the blades 8i) are secured thereto in a manner to provide the desired pitch for autorotation. However, when the rubber band motor 'I6 is wound, a greatly increased longitudinal tension is exerted on the side bars lil causing them to bow outwardly, as shown in Fig. 12. Such outward bowing causes the blades S9 to assume an increased pitch angle which is so calculated as to be the desired pitch for rapid ascent. In order to render the outward bowing of the side bars 1S sufficient to attain the desired pitch angle of the blades 8E), I may coni-lne the bowing of the side bars to a predetermined portion of the length thereof :I may eenneet .the .side bars at Point. ,etwee .be upper' .and lower. rotors by trio .lwrv'zbieb in the vpresent .Stance of reuri/.er1.term shown in Ff .'95 The l .e strip .8 holds the side hars to .to .a Silbetentielly constant seating so .that ybowing of tbeeiele bere due te the. tension of therubber bend meter when wound will .occur in that por.- tiorl .lying between .the reenercing member y8l elle .the upper end thereof. Such' bowing isof a. Sharper ,curvature than it .the bowing were permitted throughout the entire length of the side here and consequently .a greater angle of rtoh for tlieblades Bn may thereby be attained.

In all of the forms 'shown herein the rubber bend motor may .be wound by grasping .the body structure in one hand androtating the lower. roter in the correct direction. when the lllhbel band mOtQr has been wound to the vdesired extent, the lower rotor is held against rotation until the upper rotor is turning 'at vthe desired speed. v.The lower rotor is then released and rotates in the opposite' direction to the upper rotor, the entire device being lifted rapidly. The .upperl rotor in all of these' :forms is of suf.- iicientV size so that'l .the rubber band motor can.- not expend its power in a .very short time.. .Conf sequelttly the power drive thereof will .occur for a substantial period ,of` time, causing the device to ascend to quite a height'. When the power is expended, the blades of the upper rotor in .each

of the forms will reassume their normal position at a pitch angle suitable to produce autorotation thereof .ld the device. descends smoothly in an upright position and at a relatively slow Speed. S `l; claim;

l. A toy helicopter comprising a body structure, a lower bladed rotor rotatably mounted on the lower end of. said structure, a drive motor mounted in said'bo'd'yv structurer` and connected to said rotor and said body structure to elect opposite rotation thereof, a flexible U-shaped member having a central portion rigidly secured to the upper portion of said body structure and flexible arms extending upwardly, and a pair of transversely tiltable elongated blades fixed at their inner ends to the upper ends of said arms, the longitudinal axes of said blades extending substantially perpendicularly with respect to the plane of movement of said flexible arms whereby said arms tend by centrifugal force to bend outwardly under the driving force of said motor to increase the pitch .of said blades.

2. A toy helicopter comprising a tube, a lower bladed rotor rotatably mounted on the lower end of said tube, drive means mountedv in said tube and connected to said lower rotor and said tube to e'ect opposite rotation thereof, and an upper rotor comprising a pair of elongated transversely tiltable blades xed at their inner ends to a bowed intermediate portion rigidly secured to said tube and adapted to ex by oentrifugal force when driven by said drive means, the longitudinal axis of said blades extending generally perpendicularly with respect to the plane of flexing movement of said bowed portion whereby the pitch of the blades is increased upon said flexing movement.

3. A toy helicopter comprising a tube, a lower bladed rotor rotatably mounted on the lower end of said tube, drive means mounted in said versely tiltable blades xedly connected by a downwardly bowed intermediate portion centrally apertured to lit over said tube, and means' for rigidly securing said portion to said tube, said portion being so shaped adjacent said blades as to render it flexible and the longitudinal axes of said blades extending substantially perpendicularly with respect to the plane of exing movement of said bowed portion whereby centrifugal force created by rotation by said drive means will increase the pitch of the blades.

A: A toy helicopter comprising a tube, a cap frictionally secured on the lower end of said tube, a lower rotor having blades of fixed pitch rotatably carried by said cap, a plug frictionally engaged in the upper end of said tube and rigid therewith, a rubber band motor within said tube connected at one end to said lower rotor and at its other end to said plug, and an upper rotor comprising a pair of elongated transversely tiltable blades xedly mounted at their inner ends onAa bowed connecting portion rigidly secured to said tube, said portion normally holding said blades at a pitch suitable for autorotation on descent and adapted to ex by centrifugal force when driven by said motor, and the longitudinal axes of said blades extending substantially perpendicularly with respect to the plane of flexing movement of said portion whereby the pitch of said blades is increased upon said flexing movement.

5. A toy helicopter comprising a frame comprising a pair of laterally spaced elongated side bars connected at their ends, a bladed rotor rotatably mounted in the lower end of said frame, a rubber band motor extending within said frame and connected at one end to said rotor and at its other end to the other end of said frame, a second rotor comprising a pair of elongated transversely tiltable blades. and a flexible U-shaped member having its central portion secured to said other end of the frame and its arms extending upwardly therefrom and secured to said blades, the arms of said member being adapted to ex outwardly under centrifugal force created by the driving force of said motor and the longitudinal axes of said blades extending substantially perpendicularly with respect to the plane of ilexing movement of said arms whereby the pitch of said blades is increased upon said iiexing movement.

6. A toy helicopter comprising a frame comprising a pair of laterally spaced elongated side bars bent at their ends to form interconnecting portions, a bladed rotor rotatably mounted in the lower interconnecting portion, a rubber band motor connected at one end to said rotor and at its other end to the other interconnecting portion, a iiexible U-shaped member having its central portion rigidly secured to said other interconnecting portion with the arms of the U extending upwardly beyond said frame and longitudinally therewith, and a pair of elongated blades secured to the free ends of said arms, said blades having their longitudinal axes extending angularly with respect to said arms and said arms being adapted to ilex outwardly by centrifugal force to increase the pitch of said blades as an incident to the operation of said motor.

ROY R. CARRINGTON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

